Hannah, ND 58239 Frost Dates
Hannah, ND: when does the frost end?
Typically, the last spring freeze lands around 05/18, roughly 263 days out. Fall's first freeze usually shows up around 09/23, roughly 127 days after the last spring frost.
Hannah sits in USDA Zone 3b (-35 to -30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 4 weeks until Hannah's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/18 isn't a guarantee
05/18 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Hannah against the rest of the dataset
At roughly 127 frost-free days, Hannah places 38,676 of 40,283 ZIP codes in this dataset. Within ND, it ranks 354 of 405.
Learn more
Before leaning on 58239's figures: local microclimates explains what one yard in Hannah can differ from the 58239 normal, while zone vs. frost date explains why Zone 3b and Hannah's frost date answer different questions.